Cam operated range timer switch



March 10, 1964 Filed Dec. 18, 1961 W. S. ZAGORSKI ETAL CAM OPERATED RANGE TIMER SWITCH 3 Sheets-Sheet 1 w. s. zA-GoRsKl ETAI. 3,124,668 CAM QPERATED RANGE TIMER swI'rcH 'Mmh 1o, 1964 y Alive/V763- Mardi 10 1964 w. s. zAGoRsKl ETAL 3,124,668

CAM OPERATED RANGE TIMER SWITCH Filed Dec. 18, 1961 3 Sheets-Sheet 5 United States Patent O 3,124,668 CAM PERATED RANGE TMER SWITCH Wladysiaw S. Zagorski and Gerhard K. Losert, Morrison,

Ill., assignors to General Electric Company, a corporation of New York Filed Dec. 18, 196i, Ser. No. 160,101 12 Claims. (Cl. 20th-68) This invention relates to time switches of the electric range timer ty'pe and is particularly applicable tothe type of range timer having a means for automatically controlling the oven of 4an electric range.

Modern electric range timers often include means 4for .setting the stop time, i.e., the time at which the oven is to be turned off, and means for setting the cooking period, i.e., the number of hours that the food is to be baked or cooked. ln using such a timer, a housewife may set her oven for automatic operation by adjusting each of these two setting means of her range timer to the desired positions. For this type of range timer, the housewife need not compute the star-t or oven turn-on time, since this .time is automatically set to the correct value by the timer when the stop time and cooking period are properly set.

It is desirable that range timers of the aforementioned type be of reliable, foolproof, and inexpensive construction. It is also advantageous for these range timers to include a simple and efiicient means for independently setting the stop time `and the cooking period and for reading out or self-erasing the cooking period indication during the cooking period. Prior art range timers which provide these features have generally proven to be so complicated in structure and gearing as to be 4unduly expensive. For example, the mechanism of these timers which provides the self-erasing of the cooking period in.- dication has heretofore generally required a relatively large number `of parts, thereby adding undesirably to the cost of the over-all timer.

Accordingly, an object of this invention is to provide an improved range timer having an independent means for setting the stop time and the cooking period, and a simple and eicient means for achieving self-erasing indication of the cooking period.

Another object of the present invention is -to provide an improved range timer which is inexpensive, reliable, and durable.

A further object of the present invention is to provide an improved range timer having an eiicient and simplified means for setting and operating the timer switch in response to the desired stop time `and hours-to-cook time.

A still further object of this invention is to provide an improved range timer having independent means for setting the stop time and the cooking period, and a differential mechanism integrally associated with the means for set-ting the cooking period.

In accordance with the present invention, in one form thereof, there is provided an improved range timer having a rotatable control element whose iaxial movement controls the operation of a switch. This control element is mounted in coaxial relationship with a rotatable cam, and axial movement of the control element is responsive to its rotational position relative to the cam. The cam is an integral part of a first manually operable setting means and is rotatable thereby to a predetermined position Yfor setting the stop time. A second manually operable setting means is provided for rotating the control element to a predetermined position for setting the cooking period. `Cooperating means is provided on the element and the cam dor moving the element between a first axial position when the cam and element have the same relative angular location and a second axial position when the cam and element have different 4relative angnlar locations. A motor driven means is provided for engaging and rotating the element at a xed speed when the element is in its second axial position. The switch is operable in response to the axial movement of the element. With this arrangement, an improved differential gearing means is provided to effectively interconnect the second setting means with the control element and the cam by `a minimum number of parts. YThis differential gearing means is disposed in concentric integrated relation with the second setting means and it is connected to the control element and cam so that it allows independent setting of the cam by the stop time setting means and independent setting of the control element by the cooking period setting means, -with self-erasing of the indication of the cooking time remaining during the cooking period. Such an 'arrangement of the first and second setting means and the differential gearing means pro-vides a compact and efficient range timer mechanism which is very simplified in structure and low in cost.

By a further `aspect of the present invention, there is provided an improved arrangement for cooperatively associating the axially movable and rotatable control element with the cam. This improved arrangement may, of course, be combined with the aforesaid structure to provide a particularly desirable range timer. In this arrangement, the rotatable element has three cam following lugs formed thereon. These lugs extend generally in a direction parallel to the `axis of rotation of the element and are disposed at different radial distances from this axis. The outermost ends of the lugs are in a plane disposed in perpendicular relationship to the axis of the element. The ends of the lugs cooperate with Ithree similarly located recesses Iformed in the cam to provide an improved controlled supporting engagement of the lug with the cam after setting. Such an arrangement of the three lugs of the control element and the three cooperating recesses of the cams provides an eflicient and improved means -for controlling the coaction between the element and the cam to operate the switch in response to axial movement of the control element.

By further aspects of the present invention, additional desirable yfeatures may be included in the range timer, and the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as our invention. The invention, however, as to organization and method of operation, together with further l'objects and advantages thereof, may best be understood by reference to the following description when taken `in conjunction with the accompanying drawings, in which:

FIG. 1 is a front elevation vie-w of an timer embodying the thereof;

FIG. 2 is a bottom view of the range timer of FIG. l;

FIG. 3 is a fragmentary sectional view partially broken away to show structural `details of the cam, the switch control means, the differential gearing means, and the switch actuating means in the off position; Y

FIG. 4 is a fragmentary sectional view, partially broken away, to show the stop cook time assembly, the switch actu-ating means, and the fsw/itch, with the switch in the on position; dotted lines in this View show the position of the switch actuator and movable switch blades when the range timer is in the set position;

FIG. 5 is a rear detail View of the switch control assembly;

FlG. 6 is a rear detail view of the face of the cam;

FIG. 7 is a perspective View of the pivoted plate of the switch actuating assembly; and

FIG. 8 is a fragmentary exploded perspective view of the Various gears and elements located between the front improved range present invention in one form yand back plates of the timer near the hours-to-cook and stop cook time setting shafts.

Referring to FIGS. l and 2, the invention is shown in one form embodied in a range timer 1) having a clock 11 and a pair of rotatable time indicators 12 and 13 disposed in an in-line relationship with clock 11, on one side thereof, respectively. Clock 11 contains a central setting shaft 14 upon which are mounted the hour, minute and second hands 15, 16, and 17, respectively, Rotatable time indicators 12 and 13 are circular discs ixedly mounted on setting shafts 18 and 19, respectively. Clock shaft 14 and setting shaft 19 are rotatably journalled in front and rear supporting plates 2Q and 21 respectively with their front end portions extending outwardly through front plate 20 and terminating in manually operable setting knobs 22 and 24, respectively. Setting shaft 18 is rotatably journalled in front plate 20 and extends outwardly therefrom to terminate in manually operable setting knob 23.

The circular face of time indicator 12 is divided into twelve angularly spaced hourly designations 25 and is used to set the iinish or stop time of the desired cooking period, being hereinafter referred to as the stop time indicator. The rotatable time indicator 13 has a partially circular portion of its face divided into nine hourly designations 26 to set the cooking time, and off and manna designations 27 and 28. The off and manual designations 27 and 23 serve to indicate to the housewife corresponding conditions of oven energization. Rotatable time indicator 13 i-s hereinafter referred to as the cooking period indicator. The front face plate 311, as shown in FIG. 2, contains the clock face and covers the stop time and cooking period indicators 12 and 13, except for a pair of windows 31, 32 exposing only small angular portions of these indicators.

To simply and compactly arrange a clock mechanism 35, a stop time setting means 36a, a cooking period setting means' 36b, and switch controlling and actuating means 37 in the improved timer 1t), as shown in FIG. l, the axes of shafts 14, 13, and 19 are disposed in spaced apart vparallel relationship in the same plane, and the switch controlling and actuating mechanism 37 is located in concentric relationship to the stop time setting means 36a. T-he plane in which the axes of shafts 14, 18, and 19 are located cuts perpendicularly through plates Ztl, 21, and 3i?. The clock mechanism 35, setting means 36a, 36b, and part of the switch controlling and operating mechanism 37 are carried generally between and supported by the front and rear supporting plates 2t) and 21 (as shown in FIG. 3), except for indicators 12 and 13 which are located between plates 20 and 30 (as shown in FIG. 2).

An oven controlling switch 38 is mounted on rear plate 21 directly behind the switch operating and actuating mechanism 37. (See FIGS. 2 and 3.) An electric motor 39 is also mounted on rear plate 21 behind clock mechanism 35 (FIG. 2). As will be more fully explained lhereinafter, manually operable setting shafts 13 and 19 function through their respective setting means 36a, 3612 to cock and adjust the times of operation of switch 3S, while motor 39 functions to drive the clock mechanism 35 and to operate the switch controlling mechanism 37. Shaft 19 also functions to permit direct manual actuation of oven switch 38 between open and closed positions, and the motor 39 also functions to drive out or self erase the cooking period indicator 13 as the cooking period progresses.

Referring to FIGS. 2 and 3, the construction of the clock mechanism 35, manual setting means 36a, 36]? and switch controlling mechanism 37 will now be described. Clock mechanism 35 comprises a minute gear assembly 41 and an hour gear assembly 42-concentrically journalled on clock shaft 14. The minute and hour gear assemblies 41, 42 are geared together by a reduction gear assembly 43 pivotally supported between the front and rear plates 2t) and 21. Another gear 4t) (FIG. 3) attached to the lower end of shaft 14 functions to rotate shaft 14 and control the movement of second hand 17. This second hand gear 40 is driven from motor 39 through the motor output gear 45 and a suitable gear train 46 (FIG. 3). The minute gear assembly 41 is separately driven from motor 39 through a suitable gear train 47 (FIG. 2) by the motor output pinion gear 45.

For operating the switch controlling and actuating means 37 of timer 1li in response to the movement of the clock mechanism 35, the mechanism 37 includes a tripping assembly 48. Tripping assembly 4S, as best shown in FIG. 8, preferably comprises a gear 43a having a tripping member or tab 48]; struck outwardly therefrom, and it is rotatably journalled on the inner side of rear plate 21 by means of bushing 43C. Gear 43a is constantly driven by motor 39 in a clockwise direction ofA rotation (viewing FIG. 8) at a fixed speed of one revolution in twelve hours by a gear train 49 comprising reduction gear assembly 43 and idler gears 49a and 49h. (See also FIG. 2.) The switch controlling and actuating mechanism also includes a means for controlling the switch in response to preset stop time and cooking period, and a means for cooking the switch, as shall be set forth hereinafter.

Turning now to a very important aspect of the present invention which concerns itself with the provision of an improved integrated means for setting and controlling the switch 33, attention is directed to FIGS. l, 2, and 8. For setting the range timer 1i) to the desired stop time, the aforementioned stop time setting means 36a has been provided. Setting means 3a preferably compri-ses the stop time shaft 13 with an integral cam 50 concentrically formed on its innermost end. Shaft 18 and cam Sti may, for example, be formed as a single part by means of die casting the part into a single piece of metal. The integral stop shaft 18 and stop cam 5&1 are rotatably journalled and supported upon front plate 2li by extending the shaft 18 through a suitable bearing aperture from the rearward side of plate 20, Ias shown in FIG. 2, and securing it in rotatable position by a C-shaped clip 52 (FIG. 3).

The structure of stop cam 50, as shown in FIG. 8, is such that it includes an annular external gear section 53 in continuous mesh with an idler gear 54 interposed between the stop time setting shaft 18 and the cook time ksetting shaft 19. The purpose of the meshing engagement of cam 5@ with idler gear 54, as shall become apparent hereinafter, is to provide a parallel input from stop cam 50 and a follower element 55 to a differential assembly 56, thereby preventing the setting of the stop time by rotation of shaft 1S from having any effect upon the cook time setting means Sb, except when the switch 38 is in the on or instant start position.

As shown in FIG. 3, the cam 5t) is located next to front supporting plate 2t) and between plate 2t) and rear plate 21, being journalled for rotation in either a clockwise or counterclockwise direction of rotation (viewing FIG. 8). On the rear face 57 of cam Sil (which faces toward rear plate 21), there are formed three angularly spaced arcuate discontinuities such as arcuate recesses 5S. These recesses are elongated and are disposed with the centers of their longitudinal axes at equal angles from each other. The longitudinal axes of the recesses are also located at different distances radially from the axis of rotation of the cam. Thus, as shown in FIG. 6, the longitudinal axis of recess 58a is located at the furthest distance from the axis of the cam, the longitudinal axis of recess 5319 is located at a shorter radial distance from the cam axis, and the longitudinal axis of recess 58C is located closest to the cam axis. The purpose of recesses 5S and the positioning thereof is to provide an effective means for gripping cooperation between the cam and follower element 55 when the switch is in the off or manual positions and also to provide an improved means for controlling the positioning of element 55 when the switch is in the on or set positions, as shall become apparent hereinafter.

Cam 50 also has a projectionl 59 formed on the inner surface 57 thereof. Projection 59 has its long axis at the same radial distance ,fromy the axis of the cam as does recess 58a, and is also adjacent thereto, as shown in FIG. 8. The purpose of projection 59 is twofold. It includes a side 59a which engagesy tab 51 of latching lever 62 when the shaft 19 is rotated to the manual position. This engagement of the tab 51 with the projection 59 causes the switch 38 to be actuated to the on position (shown in FIG. 4), as shall be further understood hereinafter. The other function of projection 59 is served by side 59h thereof. Side 591) engages the follower element to prevent more than a nine hour cooking period from being set.

To provide an eihcient and simplified axially movable and rotatable control means which is cooperatively associated with cam Sil for the controlling operation of switch 38, the aforementioned switch contro-lling and actuating means comprises switch control assembly 60. (See FIGS. 5 and 8.) Switch control assembly 6i! comprises follower element 55, ring gear 61 which is riveted thereto, and a spring biased latching lever 62 pivotally mounted in sandwich-like fashion between gear 61 and follower element 55 on one side 62a thereof (FIG. 5). Follower element S5, as shown in FIG. 8, includes three radially extensive arms 63 having projections 64 thereon which are extended through apertures 65 of gear 61 and riveted thereto. (See also FIG. 5.) Gear 61 and element 55 are thus rigidly fastened together.

Each of the arms 63 has a turned over lug 66 projecting outwardly therefrom in perpendicular fashion. As shown in FIG. 8, the lugs 66 thus extend in a direction parallel to the axis of element 55, with their outer ends facing cam Sil. The lugs 66 are located at different distances radially from the axis of rotation of the follower element, and the radial distance of each lug is identical to the radial distance of an associated arcuate recess 58 of the cam to enable the follower to axially cooperate with the cam. Lugs 66 thus ride upon surface 57 of cam 5l) and cooperate with the arcuate recesses 56 by axial movement of the lugs 66 of follower 5S into and out of recesses 58 of the cam, as will be explained in detail hereinafter.

Follower element 55 also cylindrical sleeve or axle 67 As shown in FIG. 8, sleeve 67 extends rearwardly from the hub 68a of element 5S. The front side of hub 68a has a recess formed therein. This recess is partially closed by washer 63h, which is fastened to element 55, as shown by dotted lines in FIG. 8, in such a manner as to provide a thin transverse slot 68 on the rear side of hub 68a. The slot 63 communicates transversely with bore 73 of sleeve 67. Latehing arm or tongue 69 of lever 62 extends transversely into slot 66 and is biased by spring 61a so that latching edge 76 is normally urged into bore 73 (as shown in FIG. 5), where it engages shoulder 71 of an elongated cylindrical pin 72 (FIG. 8). Pin 72 is slidably telescoped within bore 73 of sleeve 67 and functions to automatically cock and actuate switch 3S in a manner to be explained hereinafter.

Referring to FIGS. 3, 4, 6, and 8, the detailed construction and operation of the switch controlling assembly 60 will now be described. The three arcuate recesses 58d-58e of cam 5t) are located on different circumferential paths and accommodate similarly located lugs 66 of follower element 55 when they have the same relative angular location as these lugs. As best seen in FIGS. 6 and S, recesses Sti each have a `tapered side 74 extending in a first setting direction 75 from its deepest portion 76 (i.e., clockwise, viewing FIG. 8). Each of the recesses 58 also has a plateau or step 77 extending in an opposite or reverse setting direction, indicated by larrow 73 of FIG. 8, from its deepest central portion 76.

When the outer ends of lugs 66 are in the deepest portions 76 of their associated arcuate recesses 5S, as shown in FIG. 3, the vcam follower element 5S and assembly includes an integral hollow which is formed thereupon.

60 are in the forward axial position and angular slot 79 of latching lever 62 is not in the path of tripping member 43h of trip gear d8a. When the outer ends of lugs 66 are resting on the steps 77 of recesses 5S, the cam follower element 55 is moved rearwardly to an intermediate position (not shown) but the angular slot 79 still does not move into the path required for engagement with trip member diib. However, when the outer ends of lugs 66 of the cam follower element 55 are moved up slopes 74 onto the rear surface 57 of cam Sil (FIG. 8), as shown in full in FIG. 4, the assembly 60 including cam follower element 55 and the latched pin 72 is moved axially to its rearward position in which angular latching slot '79 moves into the path of rotation of tripping member tSb. The assembly 66 with follower element 55 is then engaged, pin 72 is unlatched, and assembly 6i? is time driven by the tripping member during the rotation of trip gear 46a.

It will thus be seen that the axial position of follower element SS and therefore the axial position of switch controi assembly 66 is dependent upon the rotational angular location of the element 55 relative to cam 56. Moreover, it will be further seen that when cam remains stationary, rotation of follower gear 61 in the setting direction 75 (FIG. 8) causes the lugs of element 5S to climb out of recess deep portions 76 onto the rear surface 57 of cam 56 while rotation of the follower gear 61 in the reverse direction 73 (FIG. 8) causes the lugs of element 5S to climb onto the plateau portion 77 of cam 5d.

It will further be seen that by using a cam follower element with three lugs 66 having their outermost ends in a plane perpendicular to the axis of the element, the lugs cooperating with three similarly located recesses 58 of the coaxial cam Sti, an eicient and improved means for controlling the coaction between the cam and element has been provided. Such an arrangement in particular, provides an improved controlled supporting engagement of the lugs with the cam after setting.

Whether or not the lugs `66 of follower element 55 are within the deepest portion 76 of recesses 58, or on the plateaus -77 of recesses 58, or they are riding on the ilat rear surface 457 of cam 5t), the rotation of cam 50 by means of setting shaft 18 also produces a corresponding rotation of the switch control assembly 6,6 un.- less slot 79 of follower latch `62 is in actual engagement with trip member 4gb of trip gear 48:1. It will be appreciated that tlLis interfering engagement between slot 79 of the latching lever and trip member @Sb will occur only when the switch control assembly `6l? in in the axial position shown in full in FIG. 4. Continued rotation of cam 56 in the setting direction 75 after such engagement between slot 79 and trip member 48h will cause the lugs 66 to slide upon rear surface 57 of cam 5t! until the lugs 66 drop into recesses 58. It will also be appreciated that rotation of trip gear 43a in its usual reverse or driving direction 78 will affect this same movement of follower element 55 along the surface of cam Sil by the driving engagement of trip member lb and latching slot 79.

Turning now to an important aspect of the present invention, attention is directed to the improved cook time setting means 36h. As shown in FIG. 3, the switch control assembly is adapted to be rotated by the cooking period set shaft 1 through a simple and very efficient differential assembly S6, which also serves as an integral part of the setting means 36b. (See also FIG. 8.) More particularly, the differential assembly 56 includes a double-faced sun gear 81 (FIG. 8) rotatably journalled to front plate Ztl on the exterior of hollow bushing 81a (FIG. 3), planetary arm 8.2 fastened to shaft 19, planetary gear S3 rotatably journalled on arm 82 and an internal dilerential gear 84 having external teeth Sdu as well as internal teeth 84b.

The differential assembly 56 is arranged concentrically ena-gees to the cook time setting means 36b and the gears 81, 83, and 84 serve both as part of the differential assembly 56 and part of the cook time setting means Bob. More particularly, the set shaft 19 is journalled for rotation between plates Ztl and 21 on the right side of timer 19, viewing FIG. 1. The largest cylindrical portion of shaft 19 (as shown in FIG. 3) is rotatably positioned within the bore of bushing 81a, and shoulder 19a of shaft 19 rotatably engages plate 21. The planetary arm S2 is rigidly secured to shaft 19, and is rotatable therewith. (See also FIG. 8.) Arm 82 carries on its front-facing side (at the outer end) the planetary gear 33 which is journalled thereto by rivet 33a.

As shown in FIGS. 3 and 8, the internal differential gear 84 is recessed on its front-facing side (i.e., the side facing plate and provides a peripheral series of internal gear teeth Mb therein for meshing engagement with planetaryk gear S3. The recessed side of the gear 84 serves to compactly receive therein arm 82, planetary gear 83, and part of sun gear 81. Planetary gear S3 is also in continuous mesh with rearmost teeth 81h (FIG. 8) of sun gear 81. The front-facing peripheral teeth 81e of sun gear 81 are in continuous meshing engagement with idler gear 54, and are thereby connected to cam 50. On its external surface, gear 84 has a peripheral series of axially elongated gear teeth 84a for continuous direct meshing engagement with follower gear 61 of the switch control assembly. (See FIG. 3). Gear 84 also includes (as shown in FIG. 8) an axial bore 34e extending therethrough, and flat annular external projecting rims 34d and 84e at each end of this bore 84C. The differential gear 84 is disposed in concentric relationship with shaft 19, with the bottom cylindrical section 1919 of shaft 19 being extended through bore `34e to rotatably support gear 84 on shaft 19. Annular rim 34e thus abuts rear plate 21, as shown in FIG. 3, and rim 34d abuts planetary arm 82 (as suggested in FlG. 8), to position gear 84 between planetary arm 82 and rear plate 21.

It will thus be seen that the differential assembly 56 represents a simple and compact mechanism concentrically disposed and integrally related to the cook time set shaft 19. The external teeth 84a of differential gear S4 are in direct and continuous meshing engagement with gear 61 of the switch control assembly dit, thereby eliminating any necessity of using idler gears to transmit rotary motion from the differential assembly or the setting means 36h to follower gear 61. For transmitting rotary motion from the stop cam Sil to the differential sun gear 81, a single idler 54 with a friction clutch member 54a fastened thereto is in mesh with cam gear section 53 as well as the front-facing peripheral teeth 81C of double-faced sun gear 81. This connection allows stop time to be set by rotation of stop time set shaft 18 without effecting any change in the setting of the hours-to-cook time. More particularly, with this arrangement, a parallel input is provided to the differential assembly 56 from the cam follower gear y61 and the cam gear 53. As a result of this parallel input arrangement, the planetary arm 32 and shaft 19 remain in the same position upon rotation of stop time shaft 1S with the switch in the off or manual positions. A detailed description of the operation of the differential assembly 56 in conjunction with the operation of the stop time setting means 36a and the cook time setting means 36h shall be set forth hereinafter.

Turning now to a discussion of the switch 3S and Switch cooking mechanism 38a of the present invention, attention is directed to FIGS. 3, 4, 5, and 7. The switch control assembly 60 is continually biased forward into engagement with cam 50 by means of tension spring 85 which acts thereupon through actuator 94 and lever 86 of the switch cocking mechanism 33a. More particularly, lever 86 is constructed from a relatively flat piece of metal and, as shown in FIG. 7, includes an aperture 87 for receiving the inwardly stepped neck d'8 of sleeve o7 therethrough. Sleeve 67 extends rearwardly (FIG. 3)

from the front side of rear plate 21 through the bore of bushing 48C (FIG. 8) and is journalled for rotation therein. The lever Y86 also includes a flat continuous surface 559 on one side thereof, and a pair of upright arms 90 which extend outwardly in perpendicular fashion from the plane of the lever on the other side thereof.

For operating a pair of movable contact blades 92 (one of which is illustrated in FIGS. 3 and 4) which are fastened in cantilever fashion to base 93 of switch assembly 38, as shown in FiG. 3, an insulative actuator 94 is pivotally mounted upon lever S6. Actuator 94 is directly operable by the uial movement of outer end '72a of shouldered pin 72. More particularly, actuator 94 includes a platform section 95 of rectangular configuration. Section 95 has a pair of spaced apart molded bosses 96 (one of which is shown in FlG. 3) extending outwardly therefrom from near one of its ends, in perpendicuiar fashion. Section 95 also has a pair of lip sections 95a formed at its left end, one of which may be seen in FIGS. 3 and 4. The lip sections 95a provide indented pivotal supporting edges 95]) for engagement with edges Sil of plate 86 (FlG. 7).

Actuator 94 also includes a hooked-shaped section 97 which is disposed downwardly from platform section 95 (viewing FlG. 3) and is engaged by hooked end 35a of tension spring SS. The other hooked end SSb of tension spring 85 is looped around a bent over tab 98 which is struck from rear plate 21 and depends therefrom. The bosses 96 of actuator 94 are extended into the sides 99a of a T-shaped slot 99 formed at the upright arms 90 on one side of lever S6. The bosses 96 thus engage near the sides 99a of the T-shaped slot and position the actuator 94 therein for pivotal movement of edges 95]: of the actuator about edges Si) of lever 36.

As shown in FIG. 3, the actuator 94 is continuously urged by the tension force of spring 85 into pivotal engagement with lever S6. A pair of transversely spaced sloped shoulders 199 (one of which may be seen in FlGS. 3 and 4) are formed in base 9.3. The switch base is fastened to the rear side of plate 21 with shoulders 100 engaging the undersides of surface S9.

When the range timer switch 38 is in the off position, as shown in FIG. 3, annular shoulder 101 of sleeve 67 of the switch control assembly 69 engages a pair of transversely extensive raised edges 192 formed on each side of aperture 87 of lever 86, the outer ends 90a of upright arms 9d are adjacent the outer surface of rear plate 21, and surface S9 of lever S6 is in engagement with the sloped shoulders 199 of base 93. Actuating shoulder 10.3 of actuator 94 thereupon engages movable contact blades 92 to hold the contacts 104 of the switch 3S in an open position.

When the range timer switch 3S is operated to the set position from its off position, shoulder 101 of follower sleeve 67 is thrust rearwardly (i.e., downwardly, viewing FlG. 3) against edges 192 of lever 86. The lever 86 thereupon swivels on annular shoulder 101 in opposition to spring 85 and pivots in a counterclockwise direction of rotation (viewing FIG. 3) so that it slopes downwardly and to the left, to where it is shown in FIG. 4. When the switch is set from the off position to the set position, surface 89 of the lever thus in effect pivots about shoulders 199 of the base. The outer ends 90a of lever arms 99 are then spaced from rear plate 21, as shown in FIG. 4. Since pin 72 is latched during the setting operation from the off position, pin end 72a thus moves rearwardly with the sleeve 67. Actuator 94 is operated by pin 72 and lever 86 to the dotted position of FIG. 4, where it holds the movable contact blades (shown by dotted lines) and contacts 194 open.

When the switch 38 is operated from the set to the on position, pin 72 is unlatched. When shoulder 71 of pin 72 is released, the end 72a of the pin moves upwardly (viewing FIG. 4) from engagement with actuator 94. Actuator 94 thereupon pivots on lever 86 to move to the position where it is shown in full in FIG. 4. The actuating shoulders 103 of actuator 94 then disengage contact blades 92 and allow the switch contacts 104 to close.

When the switch 33 is operated from the on to the o position, cam follower lugs 66 find the recesses 5S of the cam Si?. Shoulder 101 of the follower S5 then moves forwardly with control assembly 6i). Lever 86 thereupon swivels on sleeve shoulder 191' and pivots back to its original position (FIG. 3). Actuator 94 then rcturns to the position of FIG. 3, and shoulders 163 thereof open' the switch contacts.

To furnish an interval timing signal for the operator, interval timer 116 is also provided in the improved range timer 1f?. The mechanism of interval timer 110 is located on the left side of timer 10 (viewing FIG.. l), yactuates a buzzer sound at the end of a time interval and is preset by the rotary adjustment of shaft 111. Time indication for the observer of this minute timer is provided by a separate rotatable disc 112 affixed to shaft 111. Disc 112 contains appropriate indicia, the position of which may be adjusted relative to a fixed indicating line on the plate 3i). For operating interval timer 114i, gear train 113 is operated by the clock mechanism to rotate interval timing gear 114.

Turning now to a description of the over-all operation of the improved range timer 16 embodying the present invention, attention is directed to FIGS. l-4. In the operation of the range timer 1i) for time-controlled cooking, the stop time set shaft 18 is manually rotated in either a clockwise or a counterclockwise direction until the desired stop time is indicated by the rotatable time indicator 12 through window 31. The cooking period setting shaft 19 is manually rotated in a clockwise direction (viewing FIG. l) until the desired cooking period is indicated by the rotatable time indicator 13 through window 32. It is important to note that either shaft 18 or shaft 19 may be set first so that either the stop time or the cooking period may be set in any sequence; and if perchance too great a cooking interval is set, the cooking period may be readily readjusted to a lesser interval by merely rotating shaft 19 in a reverse direction to the setting direction.

As cam 5h is rotated, it carries with it and produces a corresponding rotation of switch control assembly 60 (which includes follower element 55, gear 61 and latching lever 62) in the same setting direction. Rotation of the cooking period setting shaft 19 in a clockwise direction of rotation (viewing FIG. l), however, causes planetary gear 83 to move in the same direction about sun gear 81. Planetary gear 83 drives the larger gear 84 in the same direction (i.e., counterclockwise, viewing FIG. 8). `Gear 84 then drives follower gear 61 in a counterclockwise direction of rotation 75 (viewing FIG. 8) and this causes lugs 66 of follower 55 to climb out of the deepest portion 76 of recesses 5S. Lugs 66 thus move along slope 74 onto rear surface 57 of cam Sti to thereby shift the assembly 6) axially rearward from cam 5t).

As the switch control assembly 60 moves rearwardly, sleeve 67 of the follower element 55 and pin 72 are also -driven rearwardly, the pin 72 moving with assembly 60 as a result of the engagement of shoulder 71 of pin 72 with edge 76 of latching arm 69. Annular shoulder 101 of sleeve 67 is in engagement with raised edges 162 of lever 86 and therefore moves these edges of lever 86 rearwardly. During this rearward movement, shoulder 101 of sleeve 67 causes lever S6 to pivot in a counterclockwise direction of rotation (viewing FIG. 3) about shoulders 100 of the switch base against the biasing force imparted to the lever 86 by tension spring 85. The lever 86 thereupon pivots about shoulders 100 so that it moves from a relatively horizontal position (viewing FIG. 3) to a position sloping downwardly and to the left, as generally indicated in full by FIG. 4. As the bottom end 72a of pin 72 is carried downwardly from its position as shown in FIG. 3 by the switch control assembly 6), it moves pivoted actuator 94 to the position wherein it is shown in dotted lines in FIG. 4. The actuating shoulders 103 of actuator 94 then engage the movable contact blades 92 to hold the switch contacts 164 open and the switch actuating mechanism is in cocked position by means of the stress irnparted to actuator 94 and lever 86 by tension spring 85; It will be understood that due to the biasing force imparted to actuator 94 and lever S6 by the spring S5, with the switch control assembly in its set position, sleeve 67 and pin 72 are both biased outwardly (i.e., toward front plate 20).

It will be appreciated that the angular position of tripping member 48b of trip gear 43a represents a particular time of day and that the rotation of stop time setting cam Si) alters the angular location of recesses 58 relative to the angular location of this trip member 4gb. The particular angular location of recesses 5S represents a particular stop time which is indicated upon the rotatable time indicator 12, which the rotation of cam follower gear 61 in the setting direction causes the angular slot 79 of latching lever 62 of the switch control assembly 60 to move away from its preset stop time and to approach the clock time represented by the position of tripping member 48]; of the trip gear 48a. The angle between the location of lugs 66 and recesses 58 represents the number of hours in the cooking period.

If the stop time cam 50 is set to an angular position which is less than nine hours away from the clock time represented by the position of tripping member 485, continued rotation of the switch control assembly 66 during setting of the cooking period will cause the angular slot 79 of the latching lever to engage the tripping member 48b. This causes unlatching of the engagement of lever 62 with pin 72 and effects instant starting or immediate closure of the switch to the on position. Rotation of the cooking period indicator into manual position by rotation of shaft 19 in a clockwise Idirection or clockwise rotation of shaft 19 beyond nine hours under any circumstances, is prevented by the striking of radially outermost lug 66a against the back 59b of manual stop projection 59.

If the cooking period should be set first, subsequent rotation of the stop time setting shaft 1S causes both the stop time cam 50 and the follower element S5 to rotate angularly relative to the angular location of tripping member 48h. Continued rotation of the stop time setting shaft 1S in a counterclockwise direction (viewing FIG. l) then causes the angular slot 79 of the resilient latching lever to strike the tripping member 4gb when the angular difference between the location of lugs 66 and recesses 58 is equal to the preset cooking period. This again effects unlatching of the engagement of lever 62, with pin 72 to cause instant starting or immediate closure of the switch to the on position. If the stop time shaft 18 is rotated (after setting the cooking period first) in a clockwise direction (viewing FIG. l), the slot 79 of the latching lever picks up the trip member, and a slight counterclockwise rotation of shaft 18 then unlatches pin 72 to obtain instant starting. Continued rotation in a clockwise direction (FIG. l) of the stop time setting shaft 18 beyond this point (i.e., instant starting of the switch) causes the lugs 66 of follower element 5S to slide along the surface of cam 50 toward the recesses SS, thus erasing the cooking period. Because of the differential gearing assembly 56 between the stop time cam 50 and the switch control assembly 60, this erasure of the cooking period causes a corresponding rotation of the cooking period setting shaft 19 and the rotatable time indicator 13 mounted thereon.

Once the stop time yand cooking period 'are properly set, the rotation of trip gear 48 under the influence of clock motor 39 causes the tripping member 48]; to approach and engage the angular slot 79 of latching lever 62 at a start time represented by the difference between the stop time setting and the cooking period setting. The initial rotation of tripping member 48h beyond this point of engagement (which is in a clockwise direction 73, viewing FIG. 8) causes the latching lever to pivot against the force of its biasing spring 61a (FlG. 5) and releases the latching engagement between latching edge 70 of arm 69 and shoulder 71 of actuating pin 72. The actuating pin 72 is thereupon propelled forward under the inlluence of spring 85 operating through actuator 94. Lever Se, however, is maintained in its rearward position by sleeve 67 of control assembly 6@ and this causes the actuator 94 to pivot on the lever S6, from the position where it is shown in dotted lines in FIG. 4, to the position where it is shown in full in FIG. 4 (i.e., in a counterclockwise direction of rotation). The switch 33 is thereupon closed and the oven is turned on.

The continued rotation of tripping member 48h by clock motor 39 causes the rotation of the -switch control assembly 60 and a corresponding rotation and erasure of the cooking period indication on cooking period shaft 19 through the planetary differential gearing 56 concentrically arranged on this shaft. This rotation continues until the stop time represented by the location of cam recesses 5S iis reached. Lugs 66 then enter these recesses 5S and cause a forward axial movement of the control assembly 60 under the influence of spring 8S and lever d6. The resultant forward movement of shoulder 101 of follower sleeve 67 causes the lever 6 to swivel and pivot from its on position in FlG. l to its ofi position in FlG. 3 (i.e., in a clockwise direction of rotation). The forward axial movement of the control assembly dit once again brings latching lever 62 back into latching engagement with shoulder 71 of pin 72, to prepare the assembly for the succeeding setting operation.

From the above description, it will be seen that so long as lugs 66 of control element 55 are within recess portions '76 of cam Sti, the cooking period setting shaft 19 will always be in one particular location in which the rotatable time indicator will show the word off beneath window 52. In order to close the switch so that it is independent of the clock when manual control of the oven by means of the thermostat switch is desired, it is necessary only to rotate this cooking period shaft 19 in a reverse direction from this off position (i.e., counterclockwise, viewing FlG. l). This procedure brings the manual abbreviation MAN into horizontal position under window 32 and simultaneously drives the lugs of control element 55 onto plateau portions 77 of the cam 50. This causes the control assembly 60 and the switch cocking assembly 38a to move to their intermediate position and closes the switch.

It is important that in the manua or intermediate position, pin 72 be free to move forward without interference from latching edge 7i) in order that the switch blades 92 be allowed to close completely. This is effected by the engagement of manual stop projection 59 and tab 51. More particularly, rotation of shaft 19 in a counterclockwise direction, viewing FIG. l, causes assembly 60 to enter plateau 77 and engage side 59a of the manual stop projection 59 with tab 51 of latch 62. This engagement causes latch 62 to pivot against the biasing force of its spring 61a. The latching edge 7) then pivots away from the pin latching shoulder 71. This causes pin 72 to trip forwardly into the bottom of the cam blind hole 117, to close the contacts of the switch 38.

It will now therefore be seen that the new and improved range timer of the present invention provides a very simplified means ,for independently setting the stop time and cooking period. lt will also be understood that this invention provides a simplified and very efficient differential mechanism integrally associated with the means for setting the cooking period. It will be realized further that the improved range timer of the present invention provides compact integrated and separate stop time setting and cook time setting assemblies which are conjunctively associated with very compact differential and switch operating mechanisms to obtain a simple and low cost l2 over-all timer mechanism. Such an arrangement readily lends itself to desirable iiexibility of manufacturing and design.

While in accordance with the patent statutes, we have described what at present is considered to be the preferred embodiment of our invention, it will be obvious to those skilled in the art that Various changes and modifications may be made therein without departing from the invention, and we, therefore, aim in the following claims to cover all such equivalent variations as fall within the true spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

l. A timer comprising a rotatable cam, a first manually operable setting means arranged in concentric relationship to said cam for rotating said cam to a predetermined position, an axially movable rotatable control element arranged to coact with said cam, a second manually operable setting means for rotating said element to a predetermined position, cooperating means on said element and said cam for moving said element between a iirst axial position when said cam and element have a same relative angular location and a second axial position when said cam and element have different angular locations, motor driven means for engaging and rotating said element at a fixed speed when said element is in said second axial position, switch means mounted for operation in response to the axial movement of said element, and differential gearing means disposed in concentric and integral association with said second setting means and interconnecting said second setting means with said control element and said cam to allow independent setting of said cam by said first setting means and independent setting of said control element by said second setting means.

2. A timer comprising a rotatable cam, a iirst manually operable setting means arranged inconcentric relationship to said cam for rotating said cam to a predetermined position, an axially movable rotatable control element mounted coaxial with said cam, a second manually operable setting means for rotating said element to a predetermined position, cooperating means on said element and said cam for moving said element between a first axial position when said cam and element have a same relative angular location and a second axial position when said cam and element have different angular locations, motor driven means for engaging and rotating said element at a fixed speed when said element is in said second axial position, switch means mounted for operation in response to the axial movement of said element, and differential gearing means concentric to and integrally associated with said second setting means and arranged to serve as a part of said second setting means, said differential gearing means interconnecting said second setting means with control element and said cam to allow independent setting of said cam by said first setting means and independent setting of said control element by said second setting means.

3. A timer comprising a rotatable cam, a irst manually operable setting means arranged in concentric relationship to said cam for rotating said cam to a predetermined position, an axially movable rotatable control element mounted coaxial with said cam, a second manually operable setting means for rotating said element to a predetermined position, cooperating means on said element and said cam for moving said element between a first axial position when said cam and element have a same relative angular location and a second axial position when said cam and element have different angular locations, motor driven means for engaging and rotating said element at a fixed speed when said element is in said second axial position, switch means operable in response to the axial movement of said element, and differential gearing means interconnecting said second setting means with said control element and said cam, said differential gearing means comprising kan internal gear having internal and external gear teeth, a rotatable sun gear concentrically arranged within said internal gear, and a planetary gear attached to a manually operable shaft of saidl second setting means, said planetary gear being in mesh with said sun gear and the internal gear teeth of said internal gear, the external teeth of said internal gear being interconnected with said rotatable control element, said rotatable sun gear being interconnected with said cam, the differential gearing means being concentric to and integrally associated with said second setting means and arranged to serve as a part of said secondy setting means, whereby said differential gearing means is interconnected with said rst and second setting means to allow independent setting of the cam by said first setting means and independent setting of said control element by said second setting means and so that the angular position of the manually operable shaft of said second setting means indicates the angular difference instantaneously existing between the angular locations of the cam and element when said motor driven means is rotating said element.

4. A timer comprising a rotatable cam having three angularly spaced axial depressions on Ione side thereof, a nst manually operable setting means including said cam and arranged in concentric relationship to said cam for rotating said cani to a predetermined position, `an axially movable rotatable control element coaxial with said cam, said element having three angularly spaced lug's on one side thereof, said lugs having their outermost ends in a plane perpendicular to the axis of rotation of said element and disposed for uniform :axial movement into and out of the depressions o-f the cam upon rotation of the element thereby to move the element bet-Ween respective forward and rearward axial positions, 'a second manually operable setting means for rotating said element to a predetermined position, motor driven means for engaging and rotating said element at a nxed speed when said element is in said rearward axial position, switch means operable in response to the axial movement of said element, `and differential gearing means disposed in concentric land integral association with said second setting means and interconnecting said second setting means with said control element and said cam to allow independent setting of said cam by said first setting means land independent setting of said control element by said second setting means.

5. A timer comprising fa rotatable cam. hav-ing three angularly spaced axial depressions on one side thereof, an axially movable rotatable control element coaxial 'with said cam, said element having three angularly spaced lugs on one side thereof, said lugs having their outer-most ends in a plane perpendicular to the axis of rotation 4of said element and disposed for uniform axial lmovement into and out of the depressions of the cam upon rotation of the element thereby to move the element between respective forward and rearward axial positions, and means for altring the angular relationship between the lugs of the element and the depressions -of the cam for operation of said element between said positions.

6. The timer of claim 5 wherein the three angularly spaced axial depressions of the cam )are disposed in different circumferential paths and have varying arcuate lengths, and the three lugs of the control element are like- Wise disposed in different circumferential paths for cooperative engagement with said depressions of said cam and substantial angular displacement of said lugs from their associated depressions when said lugs are outside of the depressions of said cam.

7. A timer comprising a setting shaft, a cam, a control element :and a motor driven tnip gear all rotatably mounted coaxial with one another in the order named, said cam having three angularly spaced 'axial ldepressions formed therein, said element being axially movable and having three angularly spaced axially projecting lugs 4"with generally pointed and coplanar outermost ends on one side thereof for cooperatively engaging the depressions of the cam upon rotation of said element thereby to move said element between forward 'and rearward axial'y positions, said setting shaft attached to said cam for rotating said'v cam, means independent to said shaft andV carni for rotatingV said element, a switch means, a pinA coaxial with and normally latched to said element `for actuating said switch means upon axial movement of the pin in consonance with' release of said latch, and means on saidI trip' gear for engaging said control element during rotation of said trip' gear to release said pin from said latch.

8. A timer comprising :a setting shaft, a cam integral to said shaft, a control element :and la motor driven trip gear :all rotatably mounted coaxial with one another in the order named, said cam having three angularly spaced axial depressions formed therein, said depressions of said cam being disposed in different circumferential paths and having varying arcuate lengths, said element beingaxi'ally movable and having three angular'ly spaced axially projecting lugs with generally pointed and coplanar ontermost ends on one side thereof, said lugs being disposed in different circumferential paths for cooperatively engaging the depressions of the cam upon rotation of said element thereby to move said element between forward and rearward axial positions, said setting shaft being manually operable to rotate said cam, means independent to said shaft and cam for manually rotating said element, switch means, a pin coaxial with and latched to said element for actuating said switch means upon axial movement in consonance with release of said latch, and means on said trip gear for engaging said control element during rotation of said trip gear to release said pin from said latch,

9. A timer comprising la switch, said switch including a base and at least one movable switch blade mounted thereon, a lever having one of its ends in pivotal engagement with sai-d base, an actuator cooperatively associated with said lever 4and pivotally engaging the -other end of said lever, said actuator having an extremity thereof disposed in proximity to said switch blade for operating said blade, :a control element in operative engagement with said lever, an actuating pin latched to said clement and bearing against said actuator at a position removed from its pivot, land motor `driven means for engaging and moving the element rst to release said pin to close said switch and subsequently to move said lever to open said switch.

10. A timer comprising a switch, said switch including "a base and at least one movable switch blade mounted thereon, a lever having one fof its ends in pivotal engagement with said base, an actuator cooperatively associated with said lever and pivotally engaging the other end of said lever, spring biasing means for urging said actuator into pivotal engagement with said lever, said actuator having an extremity thereof disposed in proximity to said switch blade for operating said blade, a control element in operative engagement with said lever, an actuating pin normally llatched to said element and bearing against said actuator at a position removed from its pivot, said biasing means being :ar-ranged to resiliently urge said lever into operative engagement with said element :and to resiliently urge said actuator into engagement with said pin, and motor driven means for engaging and rotatably moving the element rst to release said pin to close said switch and subsequently to move said lever to open said switch.

Y11. A timer comprising a rotatable cam, a first manually operable setting means including said cam and 1an integral manually operable shaft arranged in concentric relationship to said cam for rotating said cam to la predetermined position, an axially movable rotatable control element mounted coaxial rwith said cam, a gear coaxial |with and fastened to said element, a second manually operable setting means including a manu-ally operable shaft for rotating said element to a predetermined position, cooperating means on said element and said cam for moving said element between a lirst axial position when said cam and element have .a same relative angular location and .a second taxi-al position when said cam and element have different angular locations, motor driven means for engaging and rotating said element at a fixed speed when said element is in said second axial position, switch means operable in response to the axial movement of said element, and diierential gearing means interconnecting said second setting means with said control element and said cam, said differential gearing means comprising an internal gear having internal and external gear teeth, a rotatable sun gear ooncentrically arranged within said internal gear, fand a planetary gear attached by a radially extensive arm to the manually operable shaft of said second setting means, said planetary gear being in mesh with said sun gear and the internal gear [teeth of said internal gear, the external teeth of said internal gear being directly interconnected with the gear fastened coaxially to said rotatable ycontrol element, said rotatable sun gear being -interconnected with said cam by means of an intermediate idler gear, the diterential kgearing means being concentric to and integrally associated with said se-cond setting means and arranged to serve as a part of said second setting means, whereby said differential gearing means is interconnected with said iirst and second setting means to allow independent setting of the cam by said rst setting means and independent setting of said control element by said second setting means and to allow the angular position of the manually `operable shaft lof said second setting means to indicate the `angular difference instantaneously existing between the 4angular locations of the cam and element when said motor driven means is rota-ting said element.

12. A timer comprising a rotatable cam having three angularly spaced axial depressions on one -side thereof, a iirst manually operable setting means including said cam and arranged in concentric relationship to said cam for rotating said cam to a predetermined position, an axially movable rotatable control element coaxial |with said cam, said element having three :angularly spaced lugs on one side thereof, said lugs having their outermost ends in a plane perpendicular to the :axis of rotation of said element and disposed for uniform axial movement into and out of the depressions of the cam upon rotation o-f the element thereby to move the element between respective forward and rearward axial positions, a second manually operable setting means for rotating said element to a predetermined position, motor driven means for engaging and rotating said element at a fixed speed when said element is in said rearward axial position, a sleeve integr-al to said element and movable therewith, an actuating pin telescopically arranged in said sleeve and normally llatched to said element, switch means operable in response to :axial movements of said sleeve and said pin by means of a cooking mechanism, said mechanism including a lever in operative engagement with said sleeve, an actuator lin `operative engagement with said pin when said pin is latched, and a biasing means :arranged to resiliently urge said lever into operative engagement with said element and to resiliently urge said actuator into engagement with said pin, said motor driven means Ioperating to engage and rotate said control element irst to release said p-in to close said switch and subsequently to pivot said lever for opening said switch, differential gearing means interconnecting said second setting means with said control element and said cam, said differential gearing means being disposed in concentric relation to said second setting means and being arranged to allow independent setting of said cam by said first setting means and independent setting of said control element by said second setting means.

References Cited in the le of this patent UNITED STATES PATENTS 2,202,698 Latta May 28, 1940 2,605,833 Bliss Aug. 5, 1952 2,706,224 White Apr. 12, y1955 2,733,764 Bliss Feb. 7, 1956 2,921,150 Wotring Jan. 12, 1960 2,993,099 Doyle `luly 18, `1961 3,032,618 Johnson May l, 1962 

1. A TIMER COMPRISING A ROTATABLE CAM, A FIRST MANUALLY OPERABLE SETTING MEANS ARRANGED IN CONCENTRIC RELATIONSHIP TO SAID CAM FOR ROTATING SAID CAM TO A PREDETERMINED POSITION, AN AXIALLY MOVABLE ROTATABLE CONTROL ELEMENT ARRANGED TO COACT WITH SAID CAM, A SECOND MANUALLY OPERABLE SETTING MEANS FOR ROTATING SAID ELEMENT TO A PREDETERMINED POSITION, COOPERATING MEANS ON SAID ELEMENT AND SAID CAM FOR MOVING SAID ELEMENT BETWEEN A FIRST AXIAL POSITION WHEN SAID CAM AND ELEMENT HAVE A SAME RELATIVE ANGULAR LOCATION AND A SECOND AXIAL POSITION WHEN SAID CAM AND ELEMENT HAVE DIFFERENT ANGULAR LOCATIONS, MOTOR DRIVEN MEANS FOR ENGAGING AND ROTATING SAID ELEMENT AT A FIXED SPEED WHEN SAID ELEMENT IS IN SAID SECOND AXIAL POSITION, SWITCH MEANS MOUNTED FOR OPERATION IN RESPONSE TO THE AXIAL MOVEMENT OF SAID ELEMENT, AND DIFFERENTIAL GEARING MEANS DISPOSED IN CONCENTRIC AND INTEGRAL ASSOCIATION WITH SAID SECOND SETTING MEANS AND INTERCONNECTING SAID SECOND SETTING MEANS WITH SAID CONTROL ELEMENT AND SAID CAM TO ALLOW INDEPENDENT SETTING OF SAID CAM BY SAID FIRST SETTING MEANS AND INDEPENDENT SETTING OF SAID CONTROL ELEMENT BY SAID SECOND SETTING MEANS. 